This nonprovisional application claims priority under 35 U.S.C. xc2xa7 119(a) on Patent Application No. 2000-272889 filed in Japan on Sep. 8, 2000, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to a brake device of a motorcycle which is provided with a plurality of independent brake calipers at a rear wheel side.
2. Description of the Background Art
In Japanese Patent Publication No. 2782466 xe2x80x9cmotorcyclexe2x80x9d, a brake device of a motorcycle is proposed which mounts a brake caliper for rear brake on an arm member (swing arm). In this brake device of the motorcycle, the rear brake caliper is mounted on a support bracket of the swing arm and a brake force is applied to a brake disc of a rear wheel using this rear brake caliper.
Among motorcycles, there exists a vehicle which requires a parking brake in addition to the rear brake. To provide a caliper of this parking brake together with the rear brake caliper at the outer periphery of the brake disc, a space for mounting the parking brake caliper is necessary. However, with respect to the motorcycle disclosed in the above-mentioned publication, the swing arm covers the brake disc and hence, it is impossible to ensure the space for mounting the parking brake caliper.
In JP-A No. 230201/1999 xe2x80x9cdisc brake devicexe2x80x9d, a brake device is proposed which is provided with two kinds of calipers, that is, a rear brake caliper and a parking brake caliper. In this disc brake device, the rear brake caliper and the parking brake caliper are mounted on a mounting bracket and a boss portion of the mounting bracket is fitted on a rear wheel shaft so that the mounting bracket is supported on the rear wheel shaft.
According to this device, since it is unnecessary to mount the rear brake caliper and the parking brake caliper on a swing arm of a motorcycle, it is relatively easy to arrange two kinds of brake calipers at positions corresponding to a brake disc of a rear wheel. However, with respect to this disc brake device, since the boss portion of the mounting bracket is fitted on the rear wheel shaft, it is necessary to additionally shift the swing arm to the outside in the body width direction by an amount of thickness of the boss portion.
As a result, it is necessary to arrange the swing arm while avoiding the boss portion which is bulged in the side direction and hence, the arrangement of the swing arm receives the restriction whereby the degree of freedom of designing becomes small. Further, since the swing arm is additionally shifted to the outside in the body width direction, there may be a case that a bank angle of the motorcycle cannot be sufficiently ensured.
It is therefore an object of the present invention to provide a brake device of a motorcycle which can mount a rear brake caliper and a parking brake caliper without shifting a swing arm to the outside in the body width direction more than necessary.
To achieve the above-mentioned object, a brake device of a motorcycle supports a rear wheel with a swing arm mounted on a body, stretches a damper between the swing arm and the body, and includes first and second brake calipers to apply a brake force to a brake disc of the rear wheel. A swing arm extension portion which is extended in the rearward direction from a rear wheel shaft supporting portion is formed on the swing arm, one end of the damper is connected to a rear end of the swing arm extension portion, and the first and second brake calipers are disposed above and below the swing arm extension portion.
The swing arm extension portion which is extended in the rearward direction from the rear wheel shaft supporting portion is formed on the swing arm. A space which faces an outer periphery of an upper portion of the brake disc can be formed at an upper side of the swing arm extension portion and a space which faces an outer periphery of a rear portion of the disc brake can be formed at a lower side of the swing arm extension portion.
Accordingly, the first and second brake calipers which are arranged above and below the swing arm extension portion can be mounted on the upper and lower sides of the swing arm extension portion. In addition, it is possible to make the first brake caliper face the outer periphery of the upper portion of the brake disc and it is also possible to make the second brake caliper face the outer periphery of the rear portion of the brake disc. The rear brake caliper and the parking brake caliper can be mounted without shifting the swing arm to the outside in the body width direction more than necessary.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.